850 T5 refusing to start or properly rev Topic is solved

fantajuice · Post by **fantajuice** » 22 Aug 2021, 22:43

After standing still for a couple months due to other repairs, it now either refuses to start, or when it starts, above 5k RPM it starts sputtering. Refuses to make boost above 0.4 bar.
2.0 T5 '95 with a B5204T3 with V70 T5 16T turbo and full 3" exhaust.
Could it be the fuel pump on its way out? Or could it be the unobtanium pressure regulator?
It used to show long term fuel trim code every-so-often on OBD1 before the repairs too, now I haven't checked.

Post by **RickHaleParker** » 22 Aug 2021, 22:50

fantajuice wrote: ↑22 Aug 2021, 22:43 After standing still for a couple months due to other repairs, it now either refuses to start, or when it starts, above 5k RPM it starts sputtering. Refuses to make boost above 0.4 bar.

Hum .. did not do this before the other repairs ... does it now. What where the other repairs? Double check everything. You may of made a mistake or knocked something off when you where doing the other repairs. It happens ...

fantajuice · Post by **fantajuice** » 22 Aug 2021, 22:56

RickHaleParker wrote: ↑22 Aug 2021, 22:50
fantajuice wrote: ↑22 Aug 2021, 22:43 After standing still for a couple months due to other repairs, it now either refuses to start, or when it starts, above 5k RPM it starts sputtering. Refuses to make boost above 0.4 bar.
Hum .. did not do this before the other repairs ... does it now. What where the other repairs?

Well it started before the repairs, properly. It did have boost issues and depending on the time of day or whatever sputtered too full throttle above 5k RPM.
Engine wise I've recently replaced the injector wiring loom, the water pump and all the pulleys and belts and everything that goes along with it, the turbo and the exhaust completely. I also took out the fuel pump a couple months back(the issues were also making appearances back then) and cleaned out the filter. I also replaced a blown boost pipe and re-attached some vacuum lines.
Nothing has helped.
I started losing boost shortly after I bought the car, eventually thought it was the turbo because it was completely shot. From 1.5 bar to 0.4 bar in 6 months. It wasn't the turbo, but at least it doesn't plume out white and blue smoke anymore.

Post by **RickHaleParker** » 22 Aug 2021, 23:57

fantajuice wrote: ↑22 Aug 2021, 22:56 the turbo and the exhaust completely.

Completely meaning: Exhaust manifold, Turbo, Catalytic Converter, Resonator, Muffler and Pipes. A restriction in any of the components can cause the symptoms you have.

If you remove the Front O2 sensor and the symptoms go away or improve. You got a restriction downstream of the front O2 sensor.

fantajuice · Post by **fantajuice** » 23 Aug 2021, 00:46

RickHaleParker wrote: ↑22 Aug 2021, 23:57
fantajuice wrote: ↑22 Aug 2021, 22:56 the turbo and the exhaust completely.

Completely meaning: Exhaust manifold, Turbo, Catalytic Converter, Resonator, Muffler and Pipes. A restriction in any of the components can cause the symptoms you have.

If you remove the Front O2 sensor and the symptoms go away or improve. You got a restriction downstream of the front O2 sensor.

Completely as in completely. I replaced the exhaust manifold (old one was cracked) with a known good one and turbo from Germany. The rest is completely new. The only really new issue that formed with the latest repair is that it doesn't want to start anymore, sputtering above 4.5k rpm developed sometime in the last 6 months. When it starts it idles fine.

Post by **RickHaleParker** » 23 Aug 2021, 01:07

fantajuice wrote: ↑23 Aug 2021, 00:46 The only really new issue that formed with the latest repair is that it doesn't want to start anymore, sputtering above 4.5k rpm developed sometime in the last 6 months. When it starts it idles fine.

Have you tried giving it time to build up fuel pressure before you crank?
Shot of Diethyl ether?
Check for Air leaks?
Clean MAF sensor?
Will it start with the MAF sensor disconnected?
Will it start with the CAM sensor disconnected?

Perhaps it is time to check for new DTC codes.

fantajuice · Post by **fantajuice** » 27 Aug 2021, 10:32

Right, solved.
Found my boost leak while starting to swap out the vacuum lines. Hose before intake is busted, no clue where I can get another one.

However all the hesitation and starting issues were from a bad connection to the temperature sensor under the thermostat.

Post by **scot850** » 27 Aug 2021, 16:46

Which hose is it that has broken? There are likely used ones out there but being a 2.0l it is not a car we got over in North America.

Can you post a picture as there is always a chance a member may have one in Europe or be able to suggest where to try. My memory of 850 turbos is fading with old age (not the cars, me!!).

Neil.

Post by **RickHaleParker** » 27 Aug 2021, 22:34

fantajuice wrote: ↑27 Aug 2021, 10:32 Hose before intake is busted, no clue where I can get another one.

Elbow with a smaller hose forking off? Volvo 9161093.
Any Turbo 850 1994 - 1997.
Any Turbo 1998 C/S/V/XC70.
In other words any Turbo P80 1994 - 1998.

fantajuice · Post by **fantajuice** » 28 Aug 2021, 07:58

RickHaleParker wrote: ↑27 Aug 2021, 22:34
fantajuice wrote: ↑27 Aug 2021, 10:32 Hose before intake is busted, no clue where I can get another one.
Elbow with a smaller hose forking off? Volvo 9161093.
Any Turbo 850 1994 - 1997.
Any Turbo 1998 C/S/V/XC70.
In other words any Turbo P80 1994 - 1998.

2021-08-27.png

Nobody's selling them, got a spare from some guy who didn't need his anymore - it's almost split in half too. We don't have many turbo P80's here or nobody's willing to sell parts or part them. Absolutely none in wreckers.